Marking fibrous material



United States Patent Int. el. 0691) 9/02 US. Cl. 8164 11 Claims ABSTRACT OF THE DISCLOSURE A process for the sighting of fibrous material with a tinting color capable of being removed therefrom by subsequent washing by applying to said fibrous material a water-soluble addition copolymer consisting essentially of an ethylenically unsaturated azo or anthraquinone dye and a water soluble comonomer.

This invention relates to a process for the temporary dyeing of fibrous material with certain water-soluble colored copolymers.

It is often necessary in the textile industry to identify fibrous material in the various phases of production by sighting colors (also called fugitative tinting colors) to avoid confusing these materials with one another. These sighting colors, with which for example fibre flock prior to spinning, the yarn or the finished cloth are identified, should remain on the fibrous material during the production phases in which they are to serve their purpose, but should be easily removable for example by washing, stripping or bleaching, at least to such an extent that they are not troublesome.

Both pigment dyes in the form of suspensions and soluble dyes of a great variety of classes, for example naphthol yellow S, azo-flavin FFN, acid violet 6BN and anthosin B, have been used hitherto depending on the type of fibrous material.

Removal of sighting colors is however usually troublesome and expensive and moreover is often incomplete; defective dyeings and diminished quality of the textiles are the consequences, especially in the case of union fabrics, because these have difierent afifinities for the dyes.

The object of the present invention is to provide a process for dyeing fibrous material with sighting colors which are universally applicable and which can be removed again readily and without trouble in all cases.

We have found that fibrous materials of all kinds may be sighted in a very advantageous way during textile manufacture by using a water-soluble addition copolymer of:

(a) A dye having a polymerizable group outside its chromophoric system;

(b) A water-soluble comonomer containing in the molecule at least once the grouping and, optionally,

(c) Water-insoluble comonomers.

Addition copolymers of the said type (called hereinafter copolymers) and their production are known in principle. Water-solubility in this specification means the property of forming with water a true or colloidal solution,

The following are examples of suitable dyes (a):

CzH5 Q Q o1- N=N N orange C 2H5 C Ha-SO N=N N l B r orange NHO OCH=CH:

yellow yellow such as acrylic acid, methacrylic acid, maleic acid, fu-

maric acid and their alkali metal salts, ammonium salts and amides, N-vvinyllactams, such as N-vinyl pyrrolidone, and 2-aminoethyl acrylate and its salts.-

' Examples of comonomers (c) are esters of acrylic, methacrylic, maleic and fumaric acids having one to six carbon atoms in the ester groups, acrylonitrile,'viny l 'esters having one to eight carbon atoms, vinyl chloride, vinylidene chloride, styrene, butadiene, ethylene and propylene, but their proportion in the copolymers should not be such as to make them insoluble in water.

The amounts of the comonomers (a), (b) and (c) may be varied within wide limits; as a rule they are from 1 to 15% for (a), from 10 to 99% for (b) and from 0 to 89% for (c), percentages in each case being by Weight with reference to the total-amount of the comonomers. Methods for the production of water-soluble colored'copolymers are generally known so that further details need not be given.

The term colored copolymers includes copolymers in which the dye is a compound which is absorbent or fluorescent exclusively or mainly in ultraviolet light. Sighting colorations obtained with such copolymers have importance for special purposes, for example for the requirements of an automatically controlled course of manu- I siderable advantage over the use of conventional sighting 7,

colors. A further advantage resulting therefrom is a simplification of storage because in principle only a single type of sighting color is required for all types of fiber.

Another considerable advance isto be seen in the fact that the chemical properties of the polymeric sighting colors can be extensively adapted to the special procedures to which the fibrous material is to be subjected. For example in treatment inacid-liquors sighting colorshaving acid groups are -recommehded according to this invention. After the treatment, these colored copolymers may easily be washed out by alkali. The same is true in principle for treatment of the fibrous material in alkaline liquors. The good suitability of the sightingcolors according to this invention must be regarded as surprising because the strong polar water-solubilizing groups of the comonomers (b) would be expected to imp'art 'a. strong aflinity for fibrous materials. i

A further advantage whichis very important in practice is that the polymeric sighting colors according to this invention can be adjusted by choice of their composition Example 1 V A rayon staple cloth is padded on a padding machine with an aqueous liquor containing 15 g./l. of a copolymer of 77% of acrylamide 20% of acrylic acid and 3% of the azo dye having the formula:

CHg-Cfi I p CH5 Cl which has. been neutralized with causticjsoda solution.

The cloth is thus sighted by a tinting color having an orange pastel shade which may easily be washed out.

Example 2 NHCO-CH=CH2 Theyarn thus treated is squeezed out of a padding machine and then dried. The blue violet sighting color may be washed out easily and completely by washing with a weakly alkaline hot liquor.

Skeins of polyamide yarn and of acetate silk yarn may be sighted blue violet in the same way.

Example 3 Yarns of cotton, wool, polyester fibers, viscose rayon, acetate rayon and polyacrylonitrile fiber are impregnated on a thread impregnating machine (comprising a liquor trough, a pair of squeeze rollers, a drying tunnel and a take-up device) successively with one and the same aqueous liquor which contains per liter 50 g. of a copolymer derived from 98% of N-vinylpyrrolidone and 2% of the azo dye having the formula:

The yarns are dyed yellow in this way and are then pletely removed.

so that they are compatible with other textile assistants We claim: 1. In a process for the sighting of fibrous material with a tinting color capable of being removed therefrom by subsequent washing, the improvement'which comprises: applying to said fibrous material a Water-soluble addition copolymer consisting essentially of (a) an azo or anthraquinone dye bearinga polymerizable' vinyl group outside its chromophoric system, and

acrylic, maleic and fumaric acids with one to six carbon atoms in the ester group, acrylonitrile, vinyl esters of one to eight carbon atoms, vinyl chloride, vinylidene chloride, styrene, butadiene, ethylene and propylene, in an amount such that said copolymer remains water-soluble.

3. A process as claimed in claim 1 wherein the comonorner (b) is an a,B-unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and fumaric acid.

4. A process as claimed in claim 1 wherein the comonomer (b) is an alkali metal salt of an a,5-unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and fumaric acid.

5. A process as claimed in claim 1 wherein the comonomer (b) is an ammonium salt of an o,,B-unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and fumaric acid.

6. A process as claimed in claim 1 wherein the comonorner (b) is an amide of an 04,,B-UI1S3fL1IZitEd carboxylic acid, selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and fumaric acid.

7. A process as claimed in claim 1 wherein the colored comonorner (a) is an azo dye.

8. A process as claimed in claim 1 wherein the colored comonorner (a) is an anthraquinone dye.

9. A process as claimed in claim 1 wherein the comonomer ('b) is N-vinylpyrrolidone.

10. A process as claimed in claim 1 wherein the amount of comonorner (a) is from 1 to 15% by weight with reference to the total amount of comonomers (a) and (b).

11. A process as claimed in claim 2 wherein the amount of comonorner (a) is from 1 to 15% by weight, the amount of comonorner (b) is from 10 to 99% by weight and the amount of comonorner (c) is from 0 to 89% by weight with reference to the total amount of como-nomers.

References Cited UNITED STATES PATENTS 1,500,844 7/1924 Plauson. 2,093,651 9/1937 Widmer et al 874 X 2,473,403 6/1949 Woodward 8-18 X 3,190,850 6/1965 Burke. 3,232,692 2/1966 Wilhelm et al. 818

FOREIGN PATENTS 1,139,092 11/1962 Germany. 1,139,093 11/1962 Germany.

GEORGE F. LESMES, Primary Examiner B. BETTIS, Assistant Examiner U.S. Cl. X.R. 

